From 806c96e1473e79732d0c8e945bda18b665fcfe8f Mon Sep 17 00:00:00 2001
From: Oliver Vogel <oliver@olivervogel.net>
Date: Mon, 31 Mar 2014 11:57:43 +0200
Subject: [PATCH] fix color comparison

---
 src/Intervention/Image/Image.php |  35 +++---
 tests/ImageTest.php              | 192 +++++++++++++++++++++++++++++--
 2 files changed, 199 insertions(+), 28 deletions(-)

diff --git a/src/Intervention/Image/Image.php b/src/Intervention/Image/Image.php
index 0029b946..4652429e 100644
--- a/src/Intervention/Image/Image.php
+++ b/src/Intervention/Image/Image.php
@@ -785,23 +785,26 @@ class Image
         $color = imagecolorsforindex($this->resource, imagecolorat($this->resource, $base_x, $base_y));
 
         // compare colors
-        $matches = function($c1, $c2) use ($checkTransparency, $color_tolerance, $alpha_tolerance) {
+        $colorDiffers = function($c1, $c2) use ($checkTransparency, $color_tolerance, $alpha_tolerance) {
 
             if ($checkTransparency == true) {
 
-                $alpha_delta = abs($c1['alpha'] - $c2['alpha']);
-                return($alpha_delta <= $alpha_tolerance);
+                $alpha_delta = abs(127 - $c2['alpha']);
+                return($alpha_delta > $alpha_tolerance);
 
             } else {
 
-                $color_delta = round((
-                    abs($c1['red'] - $c2['red']) +
-                    abs($c1['green'] - $c2['green']) +
-                    abs($c1['blue'] - $c2['blue'])) / 3
-                );
-
+                $red_delta = abs($c1['red'] - $c2['red']);
+                $green_delta = abs($c1['green'] - $c2['green']);
+                $blue_delta = abs($c1['blue'] - $c2['blue']);
                 $alpha_delta = abs($c1['alpha'] - $c2['alpha']);
-                return($color_delta <= $color_tolerance && $alpha_delta <= $alpha_tolerance);
+                
+                return (
+                    $red_delta > $color_tolerance or 
+                    $green_delta > $color_tolerance or 
+                    $blue_delta > $color_tolerance or 
+                    $alpha_delta > $alpha_tolerance
+                );
             }
 
         };
@@ -816,7 +819,7 @@ class Image
             for ($y=0; $y < ceil($this->height/2); $y++) {
                 for ($x=0; $x < $this->width; $x++) {
                     $checkColor = imagecolorsforindex($this->resource, imagecolorat($this->resource, $x, $y));
-                    if ( ! $matches($color, $checkColor)) {
+                    if ($colorDiffers($color, $checkColor)) {
                         $top_y = $y;
                         break 2;
                     }
@@ -829,7 +832,7 @@ class Image
             for ($x=0; $x < ceil($this->width/2); $x++) {
                 for ($y=$top_y; $y < $this->height; $y++) {
                     $checkColor = imagecolorsforindex($this->resource, imagecolorat($this->resource, $x, $y));
-                    if ( ! $matches($color, $checkColor)) {
+                    if ($colorDiffers($color, $checkColor)) {
                         $top_x = $x;
                         break 2;
                     }
@@ -839,10 +842,10 @@ class Image
 
         // search lower part of image for colors to trim away
         if (in_array('bottom', $away)) {
-            for ($y=($this->height-1); $y >= floor($this->height/2); $y--) {
+            for ($y=($this->height-1); $y >= floor($this->height/2)-1; $y--) {
                 for ($x=$top_x; $x < $this->width; $x++) {
                     $checkColor = imagecolorsforindex($this->resource, imagecolorat($this->resource, $x, $y));
-                    if ( ! $matches($color, $checkColor)) {
+                    if ($colorDiffers($color, $checkColor)) {
                         $bottom_y = $y+1;
                         break 2;
                     }
@@ -852,10 +855,10 @@ class Image
 
         // search right part of image for colors to trim away
         if (in_array('right', $away)) {
-            for ($x=($this->width-1); $x >= floor($this->width/2); $x--) {
+            for ($x=($this->width-1); $x >= floor($this->width/2)-1; $x--) {
                 for ($y=$top_y; $y < $bottom_y; $y++) {
                     $checkColor = imagecolorsforindex($this->resource, imagecolorat($this->resource, $x, $y));
-                    if ( ! $matches($color, $checkColor)) {
+                    if ($colorDiffers($color, $checkColor)) {
                         $bottom_x = $x+1;
                         break 2;
                     }
diff --git a/tests/ImageTest.php b/tests/ImageTest.php
index ed8824bb..b6816557 100644
--- a/tests/ImageTest.php
+++ b/tests/ImageTest.php
@@ -1981,9 +1981,9 @@ class ImageTest extends PHPUnit_Framework_Testcase
         $img->trim(null, null, 100); // trim with 100 tolerance (should leave image as is)
         $this->assertEquals($img->width, 11);
         $this->assertEquals($img->height, 11);
-        $this->assertEquals('#000000', $canvas->pickColor(5, 5, 'hex'));
-        $this->assertEquals('#808080', $canvas->pickColor(3, 3, 'hex'));
-        $this->assertEquals('#ffffff', $canvas->pickColor(0, 0, 'hex'));
+        $this->assertEquals('#000000', $img->pickColor(5, 5, 'hex'));
+        $this->assertEquals('#808080', $img->pickColor(3, 3, 'hex'));
+        $this->assertEquals('#ffffff', $img->pickColor(0, 0, 'hex'));
 
         // prepare test image
         $canvas = Image::canvas(1, 1, '000000');
@@ -2017,7 +2017,7 @@ class ImageTest extends PHPUnit_Framework_Testcase
         $this->assertEquals('#804040', $img->pickColor(0, 0, 'hex'));
 
         $img = clone $canvas;
-        $img->trim(null, null, 70); // trim with 70 tolerance (should only leave 000000)
+        $img->trim(null, null, 80); // trim with 80 tolerance (should only leave 000000)
         $this->assertEquals($img->width, 1);
         $this->assertEquals($img->height, 1);
         $this->assertEquals('#000000', $img->pickColor(0, 0, 'hex'));
@@ -2026,9 +2026,177 @@ class ImageTest extends PHPUnit_Framework_Testcase
         $img->trim(null, null, 100); // trim with 100 tolerance (should leave image as is)
         $this->assertEquals($img->width, 11);
         $this->assertEquals($img->height, 11);
-        $this->assertEquals('#000000', $canvas->pickColor(5, 5, 'hex'));
-        $this->assertEquals('#804040', $canvas->pickColor(3, 3, 'hex'));
-        $this->assertEquals('#ffffff', $canvas->pickColor(0, 0, 'hex'));
+        $this->assertEquals('#000000', $img->pickColor(5, 5, 'hex'));
+        $this->assertEquals('#804040', $img->pickColor(3, 3, 'hex'));
+        $this->assertEquals('#ffffff', $img->pickColor(0, 0, 'hex'));
+
+        // prepare test image
+        $canvas = Image::canvas(1, 1, 'ffffff'); // core
+        $canvas->resizeCanvas(5, 5, 'center', false, 'd90000'); // 85%
+        $canvas->resizeCanvas(11, 11, 'center', false, '008000'); // 50%
+        $canvas->resizeCanvas(16, 16, 'center', false, '333333'); // 20%
+        $canvas->resizeCanvas(20, 20, 'center', false, '000000'); // outer
+        $this->assertEquals($canvas->width, 20);
+        $this->assertEquals($canvas->height, 20);
+        $this->assertEquals('#ffffff', $canvas->pickColor(9, 9, 'hex'));
+        $this->assertEquals('#d90000', $canvas->pickColor(7, 7, 'hex'));
+        $this->assertEquals('#008000', $canvas->pickColor(4, 4, 'hex'));
+        $this->assertEquals('#333333', $canvas->pickColor(2, 2, 'hex'));
+        $this->assertEquals('#000000', $canvas->pickColor(0, 0, 'hex'));
+        
+        $img = clone $canvas;
+        $img->trim(); // trim without tolerance (should only trim outer)
+        $this->assertEquals($img->width, 16);
+        $this->assertEquals($img->height, 16);
+        $this->assertEquals('#ffffff', $img->pickColor(7, 7, 'hex'));
+        $this->assertEquals('#d90000', $img->pickColor(5, 5, 'hex'));
+        $this->assertEquals('#008000', $img->pickColor(2, 2, 'hex'));
+        $this->assertEquals('#333333', $img->pickColor(0, 0, 'hex'));
+
+        $img = clone $canvas;
+        $img->trim(null, null, 19); // trim with 19% tolerance (should leave 20%)
+        $this->assertEquals($img->width, 16);
+        $this->assertEquals($img->height, 16);
+        $this->assertEquals('#ffffff', $img->pickColor(7, 7, 'hex'));
+        $this->assertEquals('#d90000', $img->pickColor(5, 5, 'hex'));
+        $this->assertEquals('#008000', $img->pickColor(2, 2, 'hex'));
+        $this->assertEquals('#333333', $img->pickColor(0, 0, 'hex'));
+
+        $img = clone $canvas;
+        $img->trim(null, null, 20); // trim with 20% tolerance (should trim 20% and leave 50%)
+        $this->assertEquals($img->width, 11);
+        $this->assertEquals($img->height, 11);
+        $this->assertEquals('#ffffff', $img->pickColor(5, 5, 'hex'));
+        $this->assertEquals('#d90000', $img->pickColor(3, 3, 'hex'));
+        $this->assertEquals('#008000', $img->pickColor(0, 0, 'hex'));
+
+        $img = clone $canvas;
+        $img->trim(null, null, 49); // trim with 49% tolerance (should leave 49%)
+        $this->assertEquals($img->width, 11);
+        $this->assertEquals($img->height, 11);
+        $this->assertEquals('#ffffff', $img->pickColor(5, 5, 'hex'));
+        $this->assertEquals('#d90000', $img->pickColor(3, 3, 'hex'));
+        $this->assertEquals('#008000', $img->pickColor(0, 0, 'hex'));
+
+        $img = clone $canvas;
+        $img->trim(null, null, 50); // trim with 50% tolerance (should trim 50% and leave 85%)
+        $this->assertEquals($img->width, 5);
+        $this->assertEquals($img->height, 5);
+        $this->assertEquals('#ffffff', $img->pickColor(2, 2, 'hex'));
+        $this->assertEquals('#d90000', $img->pickColor(0, 0, 'hex'));
+
+        $img = clone $canvas;
+        $img->trim(null, null, 84); // trim with 84% tolerance (should leave 85%)
+        $this->assertEquals($img->width, 5);
+        $this->assertEquals($img->height, 5);
+        $this->assertEquals('#ffffff', $img->pickColor(2, 2, 'hex'));
+        $this->assertEquals('#d90000', $img->pickColor(0, 0, 'hex'));
+
+        $img = clone $canvas;
+        $img->trim(null, null, 85); // trim with 85% tolerance (should trim 85% and leave core)
+        $this->assertEquals($img->width, 1);
+        $this->assertEquals($img->height, 1);
+        $this->assertEquals('#ffffff', $img->pickColor(0, 0, 'hex'));
+
+        $img = clone $canvas;
+        $img->trim(null, null, 100); // trim with 100% tolerance (should leave image as is)
+        $this->assertEquals($img->width, 20);
+        $this->assertEquals($img->height, 20);
+        $this->assertEquals('#ffffff', $img->pickColor(9, 9, 'hex'));
+        $this->assertEquals('#d90000', $img->pickColor(7, 7, 'hex'));
+        $this->assertEquals('#008000', $img->pickColor(4, 4, 'hex'));
+        $this->assertEquals('#333333', $img->pickColor(2, 2, 'hex'));
+        $this->assertEquals('#000000', $img->pickColor(0, 0, 'hex'));
+
+        $img = clone $canvas;
+        $img->trim(null, 'left'); // trim without tolerance (should only trim right outer)
+        $this->assertEquals($img->width, 18);
+        $this->assertEquals($img->height, 20);
+        $this->assertEquals('#ffffff', $img->pickColor(7, 9, 'hex'));
+        $this->assertEquals('#d90000', $img->pickColor(9, 9, 'hex'));
+        $this->assertEquals('#d90000', $img->pickColor(7, 7, 'hex'));
+        $this->assertEquals('#008000', $img->pickColor(4, 4, 'hex'));
+        $this->assertEquals('#333333', $img->pickColor(2, 2, 'hex'));
+        $this->assertEquals('#000000', $img->pickColor(0, 0, 'hex'));
+
+        $img = clone $canvas;
+        $img->trim(null, 'left', 19); // trim with 19% tolerance (should leave 20%)
+        $this->assertEquals($img->width, 18);
+        $this->assertEquals($img->height, 20);
+        $this->assertEquals('#ffffff', $img->pickColor(7, 9, 'hex'));
+        $this->assertEquals('#d90000', $img->pickColor(9, 9, 'hex'));
+        $this->assertEquals('#d90000', $img->pickColor(7, 7, 'hex'));
+        $this->assertEquals('#008000', $img->pickColor(4, 4, 'hex'));
+        $this->assertEquals('#333333', $img->pickColor(2, 2, 'hex'));
+        $this->assertEquals('#000000', $img->pickColor(0, 0, 'hex'));
+
+        $img = clone $canvas;
+        $img->trim(null, 'left', 20); // trim with 20% tolerance (should trim 20% and leave 50%)
+        $this->assertEquals($img->width, 16);
+        $this->assertEquals($img->height, 20);
+        $this->assertEquals('#ffffff', $img->pickColor(5, 9, 'hex'));
+        $this->assertEquals('#008000', $img->pickColor(9, 9, 'hex'));
+        $this->assertEquals('#d90000', $img->pickColor(7, 7, 'hex'));
+        $this->assertEquals('#008000', $img->pickColor(4, 4, 'hex'));
+        $this->assertEquals('#333333', $img->pickColor(2, 2, 'hex'));
+        $this->assertEquals('#000000', $img->pickColor(0, 0, 'hex'));
+
+        $img = clone $canvas;
+        $img->trim(null, 'left', 49); // trim with 49% tolerance (should leave 50%)
+        $this->assertEquals($img->width, 16);
+        $this->assertEquals($img->height, 20);
+        $this->assertEquals('#ffffff', $img->pickColor(5, 9, 'hex'));
+        $this->assertEquals('#008000', $img->pickColor(9, 9, 'hex'));
+        $this->assertEquals('#d90000', $img->pickColor(7, 7, 'hex'));
+        $this->assertEquals('#008000', $img->pickColor(4, 4, 'hex'));
+        $this->assertEquals('#333333', $img->pickColor(2, 2, 'hex'));
+        $this->assertEquals('#000000', $img->pickColor(0, 0, 'hex'));
+
+        $img = clone $canvas;
+        $img->trim(null, 'left', 50); // trim with 50% tolerance (should trim 50% and leave 85%)
+        $this->assertEquals($img->width, 13);
+        $this->assertEquals($img->height, 20);
+        $this->assertEquals('#ffffff', $img->pickColor(2, 9, 'hex'));
+        $this->assertEquals('#d90000', $img->pickColor(0, 9, 'hex'));
+        $this->assertEquals('#333333', $img->pickColor(9, 9, 'hex'));
+        $this->assertEquals('#008000', $img->pickColor(7, 7, 'hex'));
+        $this->assertEquals('#008000', $img->pickColor(4, 4, 'hex'));
+        $this->assertEquals('#333333', $img->pickColor(2, 2, 'hex'));
+        $this->assertEquals('#000000', $img->pickColor(0, 0, 'hex'));
+
+        $img = clone $canvas;
+        $img->trim(null, 'left', 84); // trim with 84% tolerance (should leave 85%)
+        $this->assertEquals($img->width, 13);
+        $this->assertEquals($img->height, 20);
+        $this->assertEquals('#ffffff', $img->pickColor(2, 9, 'hex'));
+        $this->assertEquals('#d90000', $img->pickColor(0, 9, 'hex'));
+        $this->assertEquals('#333333', $img->pickColor(9, 9, 'hex'));
+        $this->assertEquals('#008000', $img->pickColor(7, 7, 'hex'));
+        $this->assertEquals('#008000', $img->pickColor(4, 4, 'hex'));
+        $this->assertEquals('#333333', $img->pickColor(2, 2, 'hex'));
+        $this->assertEquals('#000000', $img->pickColor(0, 0, 'hex'));
+
+        $img = clone $canvas;
+        $img->trim(null, 'left', 85); // trim with 85% tolerance (should trim 85% and leave core)
+        $this->assertEquals($img->width, 11);
+        $this->assertEquals($img->height, 20);
+        $this->assertEquals('#ffffff', $img->pickColor(0, 9, 'hex'));
+        $this->assertEquals('#d90000', $img->pickColor(0, 8, 'hex'));
+        $this->assertEquals('#000000', $img->pickColor(9, 9, 'hex'));
+        $this->assertEquals('#333333', $img->pickColor(7, 7, 'hex'));
+        $this->assertEquals('#008000', $img->pickColor(4, 4, 'hex'));
+        $this->assertEquals('#333333', $img->pickColor(2, 2, 'hex'));
+        $this->assertEquals('#000000', $img->pickColor(0, 0, 'hex'));
+
+        $img = clone $canvas;
+        $img->trim(null, 'left', 100); // trim with 100% tolerance (should leave image as is)
+        $this->assertEquals($img->width, 20);
+        $this->assertEquals($img->height, 20);
+        $this->assertEquals('#ffffff', $img->pickColor(9, 9, 'hex'));
+        $this->assertEquals('#d90000', $img->pickColor(7, 7, 'hex'));
+        $this->assertEquals('#008000', $img->pickColor(4, 4, 'hex'));
+        $this->assertEquals('#333333', $img->pickColor(2, 2, 'hex'));
+        $this->assertEquals('#000000', $img->pickColor(0, 0, 'hex'));
 
         // prepare test image
         $canvas = Image::canvas(1, 1, '000000');
@@ -2062,11 +2230,11 @@ class ImageTest extends PHPUnit_Framework_Testcase
 
         $img = clone $canvas;
         $img->trim('transparent', null, 100);
-        $this->assertEquals($canvas->width, 11);
-        $this->assertEquals($canvas->height, 11);
-        $this->assertEquals('rgba(0, 0, 0, 0.00)', $canvas->pickColor(0, 0, 'rgba'));
-        $this->assertEquals('rgba(255, 255, 255, 0.50)', $canvas->pickColor(3, 3, 'rgba'));
-        $this->assertEquals('rgba(0, 0, 0, 1.00)', $canvas->pickColor(5, 5, 'rgba'));
+        $this->assertEquals($img->width, 11);
+        $this->assertEquals($img->height, 11);
+        $this->assertEquals('rgba(0, 0, 0, 0.00)', $img->pickColor(0, 0, 'rgba'));
+        $this->assertEquals('rgba(255, 255, 255, 0.50)', $img->pickColor(3, 3, 'rgba'));
+        $this->assertEquals('rgba(0, 0, 0, 1.00)', $img->pickColor(5, 5, 'rgba'));
 
         // trim gradient
         $canvas = Image::make('public/gradient.png');